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1.
Neuropharmacology ; 195: 108653, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34126123

RESUMO

Therapeutic vaccines offer a viable strategy to treat opioid use disorders (OUD) complementary to current pharmacotherapies. The candidate Oxy(Gly)4-sKLH vaccine targeting oxycodone displayed pre-clinical proof of efficacy, selectivity and safety, and it is now undergoing clinical evaluation. To further support its implementation in the clinic, this study tested critical in vivo neuropsychopharmacological properties of the Oxy(Gly)4-sKLH vaccine in rats. While repeated immunizations with Oxy(Gly)4-sKLH were necessary to maintain the antibody response overtime, exposure to free oxycodone did not boost oxycodone-specific antibody levels in vaccinated rats, limiting concerns of immune-related side effects. Immunization with Oxy(Gly)4-sKLH achieved sustained antibody titers over a period of five months following initial vaccination, supporting its potential for providing long-lasting protection. In vivo studies of selectivity showed that vaccination prevented oxycodone-induced but not methadone-induced antinociception, while still preserving the opioid antagonist naloxone's pharmacological effects. Vaccination did not interfere with fentanyl-induced antinociception or fentanyl distribution to the brain. These in vivo data confirm the previously reported in vitro selectivity profile of Oxy(Gly)4-sKLH. Vaccination extended oxycodone's half-life up to 25 h compared to control. While vaccination reduced the reinforcing efficacy of oxycodone in an intravenous self-administration model, signs of toxicity were not observed. These rodent studies confirm that active immunization with Oxy(Gly)4-sKLH induces highly specific and long-lasting antibodies which are effective in decreasing the reinforcing effects of oxycodone while preserving the efficacy of medications used to treat OUD and overdose.


Assuntos
Anticorpos , Encéfalo/efeitos dos fármacos , Transtornos Relacionados ao Uso de Opioides/tratamento farmacológico , Oxicodona , Vacinação , Vacinas/farmacologia , Animais , Fentanila/farmacologia , Masculino , Ratos
2.
J Hum Nutr Diet ; 34(2): 345-355, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-32869430

RESUMO

BACKGROUND: Low muscularity and malnutrition at intensive care unit (ICU) admission have been associated with negative clinical outcomes. There are limited data available evaluating the validity of bedside techniques to measure muscle mass in critically ill adults. We aimed to compare bedside methods for muscle mass assessment [bioimpedance spectroscopy (BIS), arm anthropometry and subjective physical assessment] against reference technology [computed tomography (CT)] at ICU admission. METHODS: Adults who had CT scanning at the third lumbar area <72 h after ICU admission were prospectively recruited. Bedside methods were performed within 48 h of the CT scan. Pearson's correlation compared CT muscle area with BIS-derived fat-free mass (FFM) (kg) and FFM-Chamney (kg) (adjusted for overhydration), mid-upper arm circumference (cm) and mid-arm muscle circumference (cm). Depleted muscle stores were determined using published thresholds for each method. Cohen's kappa (κ) was used to evaluate the agreement between bedside and CT assessment of muscularity status (normal or low). RESULTS: Fifty participants were enrolled. There were strong correlations between CT muscle area and FFM values and mid-arm muscle circumference (P < 0.001). Using FFM-Chamney, all six (100%) participants with low CT muscle area were detected (κ = 0.723). FFM-BIS, arm anthropometry and subjective physical assessment methods detected 28%-38% of participants with low CT muscle area. CONCLUSIONS: BIS-derived FFM using an adjustment algorithm for overhydration was correlated with CT muscle area and had good agreement with muscularity status assessed by CT image analysis. Arm anthropometry and subjective physical assessment techniques were not able to reliably detect participants with low CT muscle area.


Assuntos
Unidades de Terapia Intensiva , Músculo Esquelético , Adulto , Composição Corporal , Estudos Transversais , Impedância Elétrica , Humanos , Músculo Esquelético/diagnóstico por imagem , Estudos Prospectivos , Tomografia Computadorizada por Raios X
3.
Mol Pharm ; 16(6): 2364-2375, 2019 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-31018096

RESUMO

This study focused on formulating conjugate vaccines targeting oxycodone and heroin for technology transfer, good manufacturing practice (GMP), and clinical evaluation. Lead vaccines used the highly immunogenic carrier protein keyhole limpet hemocyanin (KLH), which poses formulation problems because of its size. To address this barrier to translation, an oxycodone-based hapten conjugated to GMP-grade subunit KLH (OXY-sKLH) and adsorbed on alum adjuvant was studied with regard to carbodiimide coupling reaction time, buffer composition, purification methods for conjugates, conjugate size, state of aggregation, and protein/alum ratio. Vaccine formulations were screened for post-immunization antibody levels and efficacy in reducing oxycodone distribution to the brain in rats. While larger conjugates were more immunogenic, their size prevented characterization of the haptenation ratio by standard analytical methods and sterilization by filtration. To address this issue, conjugation chemistry and vaccine formulation were optimized for maximal efficacy, and conjugate size was measured by dynamic light scattering prior to adsorption to alum. An analogous heroin vaccine (M-sKLH) was also optimized for conjugation chemistry, formulated in alum, and characterized for potency against heroin in rats. Finally, this study found that the efficacy of OXY-sKLH was preserved when co-administered with M-sKLH, supporting the proof of concept for a bivalent vaccine formulation targeting both heroin and oxycodone. This study suggests methods for addressing the unique formulation and characterization challenges posed by conjugating small molecules to sKLH while preserving vaccine efficacy.


Assuntos
Transtornos Relacionados ao Uso de Opioides/prevenção & controle , Vacinas Conjugadas/química , Animais , Hemocianinas/metabolismo , Heroína/toxicidade , Humanos , Oxicodona/toxicidade , Ratos , Vacinas/química , Vacinas/uso terapêutico , Vacinas Conjugadas/uso terapêutico
4.
J Chem Phys ; 147(1): 013914, 2017 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-28688387

RESUMO

The ultraviolet photochemistry of 2-bromothiophene (C4H3SBr) has been studied across the wavelength range 265-245 nm using a velocity-map imaging (VMI) apparatus recently modified for multi-mass imaging and vacuum ultraviolet (VUV, 118.2 nm) universal ionization. At all wavelengths, molecular products arising from the loss of atomic bromine were found to exhibit recoil velocities and anisotropies consistent with those reported elsewhere for the Br fragment [J. Chem. Phys. 142, 224303 (2015)]. Comparison between the momentum distributions of the Br and C4H3S fragments suggests that bromine is formed primarily in its ground (2P3/2) spin-orbit state. These distributions match well at high momentum, but relatively fewer slow moving molecular fragments were detected. This is explained by the observation of a second substantial ionic product, C3H3+. Analysis of ion images recorded simultaneously for several ion masses and the results of high-level ab initio calculations suggest that this fragment ion arises from dissociative ionization (by the VUV probe laser) of the most internally excited C4H3S fragments. This study provides an excellent benchmark for the recently modified VMI instrumentation and offers a powerful demonstration of the emerging field of multi-mass VMI using event-triggered, high frame-rate sensors, and universal ionization.

5.
Neuroscience ; 319: 233-45, 2016 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-26791525

RESUMO

Binge eating is defined by the consumption of an excessive amount of food in a short time, reflecting a form of hedonic eating that is not necessarily motivated by caloric need. Foods consumed during a binge are also often high in fat and/or sugar. Ghrelin, signaling centrally via the growth-hormone secretagogue receptor (GHSR), stimulates growth hormone release and appetite. GHSR signaling also enhances the rewarding value of palatable foods and increases the motivation for such foods. As ghrelin interacts directly with dopaminergic reward circuitry, shown to be involved in binge eating, the current studies explored the role of GHSR signaling in a limited access model of binge eating in mice. In this model, mice received either intermittent (INT) or daily (DAILY) access to a nutritionally complete high-fat diet (HFD) for 2h late in the light cycle, alongside 24-h ad libitum chow. In CD-1 mice, 2-h exposure to HFD generated substantial binge-like intake of HFD, as well as a binge-compensate pattern of 24-h daily intake. INT and daily groups did not differ in 2-h HFD consumption, while INT mice maintained stable intake of chow despite access to HFD. GHSR knock-out (KO) and wild-type (WT) mice both binged during HFD access, and exhibited the same binge-compensate pattern. INT GHSR KO mice did not binge as much as WT, while DAILY KO and WT were comparable. Overall, GHSR KO mice consumed fewer calories from HFD, regardless of access condition. GHSR KO mice also had reduced activation of the nucleus accumbens shell, but not core, following HFD consumption. These data support the ability of INT HFD in mice to induce a binge-compensate pattern of intake that emulates select components of binge eating in humans. There also appears to be a role for GHSR signaling in driving HFD consumption under these conditions, potentially via mediation of reward-related circuitry.


Assuntos
Bulimia/metabolismo , Dieta Hiperlipídica/efeitos adversos , Comportamento Alimentar/fisiologia , Grelina/metabolismo , Animais , Modelos Animais de Doenças , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Knockout , Núcleo Accumbens/metabolismo , Proteínas Proto-Oncogênicas c-fos/análise , Proteínas Proto-Oncogênicas c-fos/biossíntese , Transdução de Sinais/fisiologia
6.
Rev Sci Instrum ; 85(2): 023306, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24593353

RESUMO

The time resolution achievable using standard position-sensitive ion detectors, consisting of a chevron pair of microchannel plates coupled to a phosphor screen, is primarily limited by the emission lifetime of the phosphor, around 70 ns for the most commonly used P47 phosphor. We demonstrate that poly-para-phenylene laser dyes may be employed extremely effectively as scintillators, exhibiting higher brightness and much shorter decay lifetimes than P47. We provide an extensive characterisation of the properties of such scintillators, with a particular emphasis on applications in velocity-map imaging and microscope-mode imaging mass spectrometry. The most promising of the new scintillators exhibits an electron-to-photon conversion efficiency double that of P47, with an emission lifetime an order of magnitude shorter. The new scintillator screens are vacuum stable and show no signs of signal degradation even over longer periods of operation.

7.
Horm Behav ; 60(5): 572-80, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21872601

RESUMO

Ghrelin is an orexigenic peptide that acts within the central nervous system to stimulate appetite and food intake via the growth hormone secretagogue receptor (GHS-R). It has been hypothesized that ghrelin modulates food intake in part by stimulating reward pathways in the brain and potentially stimulating the intake of palatable foods. Here we examined the effects of chronic ghrelin administration in the ventral tegmental area (VTA) via osmotic minipumps on 1) ad libitum food intake and bodyweight; 2) macronutrient preference; and 3) motivation to obtain chocolate pellets. In the first study rats receiving ghrelin into the VTA showed a dose-dependent increase in the intake of regular chow, also resulting in increased body weight gain. A second study revealed that intra-VTA delivery of the ghrelin receptor antagonist [Lys-3]-GHRP-6 selectively reduced caloric intake of high-fat chow and reduced body weight gain relative to control and ghrelin treated rats. The third study demonstrated that food restricted rats worked harder for food pellets when infused with ghrelin than when infused with vehicle or ghrelin receptor antagonist treated rats. Finally, rats trained on an FR1 schedule but returned to ad libitum during ghrelin infusion, responded at 86% of baseline levels when they were not hungry, whereas saline infused rats responded at 36% of baseline. Together, these results suggest that ghrelin acts directly on the VTA to increase preference for and motivation to obtain highly-palatable food.


Assuntos
Preferências Alimentares/fisiologia , Grelina/fisiologia , Motivação/fisiologia , Área Tegmentar Ventral/fisiologia , Animais , Apetite/efeitos dos fármacos , Dieta Hiperlipídica , Ingestão de Alimentos/efeitos dos fármacos , Preferências Alimentares/efeitos dos fármacos , Grelina/antagonistas & inibidores , Grelina/farmacologia , Masculino , Motivação/efeitos dos fármacos , Oligopeptídeos/farmacologia , Ratos , Ratos Long-Evans , Receptores de Grelina/antagonistas & inibidores , Área Tegmentar Ventral/efeitos dos fármacos , Aumento de Peso/efeitos dos fármacos
8.
Horm Behav ; 59(1): 14-21, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20932839

RESUMO

Female rats with maternal experience display a shorter onset of maternal responsiveness compared to those with no prior experience. This phenomenon called 'maternal memory' is critically dependent on the nucleus accumbens (NA) shell. We hypothesized that activation of OT receptors in the NA shell facilitates maternal memory. In Experiment 1, postpartum female rats given 1 hour of maternal experience were infused following the experience with either a high or low dose of an OT antagonist into the NA shell and tested for maternal behavior after a 10-day pup isolation period. Females receiving a high dose of the antagonist showed a significantly longer latency to exhibit full maternal behavior after the pup isolation period compared to females that received vehicle or a high dose of antagonist in a control region. In Experiment 2, postpartum female rats were infused with either a high or low dose of OT into the NA shell after a 15-minute maternal experience and tested for maternal behavior after a 10-day pup isolation period. There were no significant differences between the females infused with OT and females treated with a vehicle infused into the NA shell or with OT infused into the control region. One possible reason for a lack of facilitation is a floor effect, since females in the control groups displayed a rapid maternal response after the pup isolation period. These findings suggest that OT receptors, likely in combination with other neurotransmitters, in the NA shell play a role in the consolidation of maternal memory.


Assuntos
Comportamento Materno/fisiologia , Memória/fisiologia , Núcleo Accumbens/metabolismo , Receptores de Ocitocina/metabolismo , Animais , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Feminino , Comportamento Materno/efeitos dos fármacos , Memória/efeitos dos fármacos , Núcleo Accumbens/efeitos dos fármacos , Ocitocina/análogos & derivados , Ocitocina/farmacologia , Período Pós-Parto/fisiologia , Ratos , Ratos Sprague-Dawley
9.
Intern Med J ; 41(6): 455-61, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19712204

RESUMO

BACKGROUND: Whether autonomic dysfunction contributes to tachycardia in cystic fibrosis (CF) is unknown. METHODS: Heart rate variability (HRV) was assessed to determine high frequency power and the low/high frequency power ratio (HF, LF/HF) as markers of vagal and sympathovagal balance, respectively, under spontaneous and controlled breathing (15 breaths per minute (bpm)) conditions in 17 CF and 17 healthy control subjects. RESULTS: Under spontaneously breathing conditions, the CF group was tachycardic (75.4 ± 11.2 vs 60.2 ± 9.0 br/min P < 0.001) and tachypnoeic (22.6 ± 5.8 vs 13.6 ± 4.1 br/min, P= 0.001) compared with controls. No significant difference in HRV was observed between groups during spontaneous or controlled breathing. Coexistent diabetes mellitus and ß(2) agonist use were not associated with altered autonomic control. During controlled breathing, the CF group showed a negative correlation between forced expiratory volume in 1 s (FEV(1)) % predicted and HF power (P= 0.013, r=-0.59) and a positive correlation between FEV(1) % predicted and LF/HF ratio (P= 0.002, r= 0.69) suggesting an exaggerated normal vagal response. CONCLUSION: CF patients have normal autonomic function.


Assuntos
Sistema Nervoso Autônomo/fisiologia , Fibrose Cística/fisiopatologia , Frequência Cardíaca/fisiologia , Taquicardia/fisiopatologia , Adulto , Fibrose Cística/complicações , Complicações do Diabetes/complicações , Complicações do Diabetes/fisiopatologia , Eletrocardiografia/métodos , Feminino , Humanos , Masculino , Mecânica Respiratória/fisiologia , Taquicardia/complicações , Adulto Jovem
10.
Mol Oral Microbiol ; 25(1): 15-24, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20331791

RESUMO

Streptococcus pneumoniae colonization of the human airway is an essential precursor for disease; however, the mechanisms by which the bacterium establishes and maintains colonization are poorly understood. It is becoming increasingly clear that S. pneumoniae expresses glycosidases that can modify many glycan structures present in the human airway, including N-linked glycans, O-linked glycans, and glycosaminoglycans. Many of these glycosidases have been shown to contribute to in vivo colonization. Although the precise role of these glycosidases during colonization remains to be elucidated, in vitro assays suggest that pneumococcal modification of host sugars may contribute to colonization in a variety of ways. Experimental evidence supports a role for pneumococcal glycosidases in providing a carbon source for growth, biofilm formation, competition with other bacteria within the airway, and exposing receptors for adherence. Herein we review the ability of S. pneumoniae to modify host sugars and the functional effects of these modifications.


Assuntos
Proteínas de Bactérias/metabolismo , Glicosídeo Hidrolases/metabolismo , Polissacarídeos/metabolismo , Mucosa Respiratória/microbiologia , Streptococcus pneumoniae/enzimologia , Streptococcus pneumoniae/fisiologia , Animais , Antibiose/fisiologia , Aderência Bacteriana , Proteínas de Bactérias/genética , Biofilmes/crescimento & desenvolvimento , Glicosídeo Hidrolases/genética , Interações Hospedeiro-Patógeno , Humanos , Neuraminidase/genética , Neuraminidase/metabolismo , Streptococcus pneumoniae/crescimento & desenvolvimento
11.
Eur J Cancer Care (Engl) ; 19(4): 492-500, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19702698

RESUMO

The objectives of this study were to identify gaps in information provision along the colorectal cancer (CRC) treatment pathway as provided by health services within the North Eastern Metropolitan Integrated Cancer Service in Victoria Australia; to evaluate the information and recommend consistent, high quality health information resources; and to recommend strategies to improve delivery of patient information. A random sample of health professionals (n= 47) from various disciplines at eight health service sites participated in semi-structured interviews regarding the types of information they provided to CRC patients. Information items were mapped against a published CRC patient management framework and evaluated. A total of 193 information items were collected with 24 items specific to CRC. Gaps in information provision were evident in the community, at diagnosis, in clinics, when treatment was determined and when completed. The quality of information delivery to CRC patients across the public health sites was variable. Resources were often unavailable, out of date and inaccessible in other languages. Results indicate a need to improve health information availability and resource delivery to all CRC patients across different health services particularly at diagnosis and after treatment. Further research is required to determine patient preferences for information about CRC.


Assuntos
Neoplasias Colorretais , Pessoal de Saúde , Necessidades e Demandas de Serviços de Saúde/normas , Educação de Pacientes como Assunto/normas , Necessidades e Demandas de Serviços de Saúde/organização & administração , Humanos , Educação de Pacientes como Assunto/organização & administração , Vitória
12.
J Urol ; 176(4 Pt 2): 1801-5; discussion 1805, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16945653

RESUMO

PURPOSE: Bladder augmentation has revolutionized the care of children with a neuropathic bladder but it remains a major surgical procedure. However, the need for subsequent bladder surgery has not been well defined in a large series with long-term followup. MATERIALS AND METHODS: We retrospectively reviewed the records of the first 500 bladder augmentations performed from 1978 to 2003 at our institution. Charts were reviewed for complications requiring additional surgery, including malignancy, bladder perforation, repeat augmentation, bowel obstruction and bladder calculi. Mean and median followup was 13.3 years. RESULTS: Complications occurred in 169 patients (34%) resulting in a total of 254 surgeries. The cumulative risk of further surgery at the bladder level was 0.04 operations per patient per year of augmentation. Three patients (0.6%) had transitional cell carcinoma, of whom all presented with metastatic disease and died. Bladder perforation occurred in 43 patients (8.6%) with a total of 53 events. Of the patients 16 (3.2%) required laparotomy for bowel obstruction and 47 (9.4%) required repeat augmentation. Bladder stones were treated in 75 patients (15%), who required a total of 125 surgeries. CONCLUSIONS: Bladder augmentation provides immeasurable improvements in quality of life but it requires lifelong dedication from the patient, family and health care providers. While the requirements for additional surgery are not trivial, 66% of our patients have not required any further surgery in the augmented bladder.


Assuntos
Bexiga Urinaria Neurogênica/cirurgia , Bexiga Urinária/cirurgia , Criança , Feminino , Humanos , Obstrução Intestinal/etiologia , Obstrução Intestinal/cirurgia , Masculino , Reoperação , Ruptura Espontânea , Cálculos da Bexiga Urinária/etiologia , Cálculos da Bexiga Urinária/cirurgia , Doenças da Bexiga Urinária/etiologia , Doenças da Bexiga Urinária/cirurgia , Procedimentos Cirúrgicos Urológicos/efeitos adversos
13.
J Urol ; 176(4 Pt 2): 1826-9; discussion 1830, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16945660

RESUMO

PURPOSE: Occult tethered cord syndrome applies to patients with signs and symptoms consistent with a caudal spinal cord malformation despite normal neuroimaging. Although several reports of successful surgical treatment exist, controversy remains with respect to patient selection and efficacy. We present a large series with excellent clinical followup, neuroimaging and urodynamic characterization. MATERIALS AND METHODS: We present our experience with 36 patients at a single institution with preoperative clinical findings, neuroimaging and urodynamics available. Postoperative outcomes were assessed clinically and with urodynamics. We determined predictive parameters to improve patient selection. RESULTS: Approximately 0.04% of pediatric urology clinic visits resulted in neurosurgical referral for the potential of an occult tethered cord. They occurred after failure of a mean of 2 years of aggressive medical management. Daytime urinary incontinence was present in 83% of patients and 47% had encopresis. Preoperative urodynamics were markedly abnormal in all patients with mean bladder capacity 55% of expected capacity. Clinical improvement in urinary symptoms was seen in 72% of patients with resolution of incontinence in 42%. Bowel symptoms improved in 88% of cases, including resolution of encopresis in 53% within 3 months of surgery. Urodynamic improvements were demonstrated in 57% of cases. We were unable to determine preoperative factors that were more likely associated with surgical success. CONCLUSIONS: In a highly select population with severe urinary and fecal dysfunction sectioning a normal-appearing filum terminale can result in significant improvement. We were unable to identify factors that may increase the chance of surgical success.


Assuntos
Cauda Equina/cirurgia , Espinha Bífida Oculta/cirurgia , Bexiga Urinaria Neurogênica/fisiopatologia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , Espinha Bífida Oculta/complicações , Espinha Bífida Oculta/diagnóstico , Bexiga Urinaria Neurogênica/etiologia , Incontinência Urinária/etiologia , Incontinência Urinária/fisiopatologia , Urodinâmica
14.
J Hum Evol ; 51(4): 395-410, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16911817

RESUMO

Remains of what appears to be a single, subadult Hadropithecus stenognathus were recovered from a previously unexcavated site at Andrahomana Cave (southeastern Madagascar). Specimens found comprise isolated teeth and cranial fragments (including the frontal processes of the orbits), as well as a partial postcranial skeleton. They include the first associated fore- and hind-limb bones, confirming the hind-limb attributions made by Godfrey and co-workers in 1997, and refuting earlier attributions by Lamberton in 1937/1938. Of particular interest here are the previously unknown elements, including a sacrum, other vertebrae and ribs, some hand bones, and the distal epiphysis of a femur. We briefly discuss the functional implications of previously unknown elements. Hadropithecus displayed a combination of characters reminiscent of lemurids, others more like those of the larger-bodied Old World monkeys, and still others more like those of African apes. Yet other characteristics appear unique. Lemurid-like postcranial characteristics may be primitive for the Archaeolemuridae. Hadropithecus diverges from the Lemuridae in the direction of Archaeolemur, but more extremely so. Thus, for example, it exhibits a stronger reduction in the size of the hamulus of the hamate, greater anteroposterior compression of the femoral shaft, and greater asymmetry of the femoral condyles. Nothing in its postcranial anatomy signals a close relationship to either the Indriidae or the Palaeopropithecidae.


Assuntos
Osso e Ossos/anatomia & histologia , Fósseis , Strepsirhini/anatomia & histologia , Animais , Madagáscar , Dente
15.
Curr Biol ; 15(23): 2075-85, 2005 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-16332532

RESUMO

BACKGROUND: Cytoplasmic dynein is the molecular motor responsible for most retrograde microtubule-based vesicular transport. In vitro single-molecule experiments suggest that dynein function is not as robust as that of kinesin-1 or myosin-V because dynein moves only a limited distance (approximately 800 nm) before detaching and can exert a modest (approximately 1 pN) force. However, dynein-driven cargos in vivo move robustly over many microns and exert forces of multiple pN. To determine how to go from limited single-molecule function to robust in vivo transport, we began to build complexity in a controlled manner by using in vitro experiments. RESULTS: We show that a single cytoplasmic dynein motor frequently transitions into an off-pathway unproductive state that impairs net transport. Addition of a second (and/or third) dynein motor, so that cargos are moved by two (or three) motors rather than one, is sufficient to recover several properties of in vivo motion; such properties include long cargo travels, robust motion, and increased forces. Part of this improvement appears to arise from selective suppression of the unproductive state of dynein rather than from a fundamental change in dynein's mechanochemical cycle. CONCLUSIONS: Multiple dyneins working together suppress shortcomings of a single motor and generate robust motion under in vitro conditions. There appears to be no need for additional cofactors (e.g., dynactin) for this improvement. Because cargos are often driven by multiple dyneins in vivo, our results show that changing the number of dynein motors could allow modulation of dynein function from the mediocre single-dynein limit to robust in vivo-like dynein-driven motion.


Assuntos
Dineínas/metabolismo , Microtúbulos/metabolismo , Modelos Biológicos , Proteínas Motores Moleculares/metabolismo , Animais , Fenômenos Biomecânicos , Bovinos , Células Cultivadas , Cinesinas/metabolismo , Microesferas , Transporte Proteico/fisiologia
16.
Eur Respir J ; 25(1): 54-61, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15640323

RESUMO

The aim of this cross-sectional study was to determine the prevalence and identify determinants of reduced bone mineral density (BMD) in adults with cystic fibrosis (CF). Adults (88) with CF (mean+/-SD age 29.9+/-7.7 yrs; forced expiratory volume in one second (FEV1) 58.2+/-21.5% of the predicted value) were studied. BMD at the lumbar spine (LS) and femoral neck (FN) and body composition were measured using dual-energy X-ray absorptiometry. Blood and urine were analysed for hormones, bone turnover markers, and the cytokines tumour necrosis factor-alpha, and interleukin-6 and -1beta. FEV1 (% pred); CF genotype; malnutrition; history of growth, development or weight gain delays; and corticosteroid use were analysed. BMD Z-scores were -0.58+/-1.30 (mean+/-SD) at the LS and -0.24+/-1.19 at the FN. Z-scores of <-2.0 were found in 17% of subjects. Subjects who were homozygous or heterozygous for the DeltaF508 mutation exhibited significantly lower Z-scores than those with no DeltaF508 allele. Multiple linear regression showed that the DeltaF508 genotype and male sex were independently associated with lower BMD at both sites. Other factors also independently associated with lower BMD included malnutrition, lower 25-hydroxyvitamin D level, lower fat-free mass and lower FEV1 (% pred). In conclusion, reduced bone mineral density in cystic fibrosis is associated with a number of factors, including DeltaF508 genotype, male sex, greater lung disease severity and malnutrition.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/genética , Fibrose Cística/epidemiologia , Fibrose Cística/genética , Mutação , Osteoporose/epidemiologia , Osteoporose/genética , Adulto , Densidade Óssea/fisiologia , Comorbidade , Estudos Transversais , Densitometria , Feminino , Predisposição Genética para Doença , Humanos , Modelos Lineares , Masculino , Análise Multivariada , Prevalência , Probabilidade , Prognóstico , Estudos Prospectivos , Fatores de Risco , Sensibilidade e Especificidade , Índice de Gravidade de Doença
17.
Infect Immun ; 69(12): 7572-82, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11705935

RESUMO

Streptococcus suis is an economically important pathogen of pigs responsible for a variety of diseases including meningitis, septicemia, arthritis, and pneumonia, although little is known about the mechanisms of pathogenesis or virulence factors associated with this organism. Here, we report on the distribution and genetic diversity of the putative virulence factor suilysin, a member of the thiol-activated toxin family of gram-positive bacteria. On the basis of PCR analysis of over 300 isolates of S. suis, the suilysin-encoding gene, sly, was detected in 69.4% of isolates. However, sly was present in a considerably higher proportion of isolates obtained from cases of meningitis, septicemia, and arthritis (>80%) and isolates obtained from asymptomatic tonsillar carriage (>90%) than lung isolates associated with pneumonia (44%). With the exception of serotypes 1, 14, and 1/14, there was no strong correlation between the presence of suilysin and serotype. Analysis of the genetic diversity of suilysin by restriction fragment length polymorphism and sequence analysis found that the suilysin gene, where present, is highly conserved with a maximum of 1.79% diversity at the nucleotide level seen between sly alleles. Assays of hemolytic activity and hybridization analysis provided no evidence for a second member of the thiol-activated toxin family in S. suis. Inverse PCR was used to characterize regions flanking sly, which in turn allowed the first characterization of the equivalent region in a strain lacking sly. Sequence comparison of these regions from sly-positive (P1/7) and sly-negative (DH5) strains indicated that two alternative arrangements are both flanked by genes with highest similarity to haloacid dehalogenase-like hydrolases (5' end) and putative N-acetylmannosamine-6-phosphate epimerases (3' end). However, sly appears to be completely absent from the alternative arrangement, and a gene of unknown function is located in the equivalent position. Finally, PCR analysis of multiple sly-positive and -negative strains indicated that these two alternative genetic arrangements are conserved among many S. suis isolates.


Assuntos
Proteínas Hemolisinas/genética , Infecções Estreptocócicas/veterinária , Streptococcus suis/genética , Doenças dos Suínos/microbiologia , Sequência de Aminoácidos , Animais , Artrite Infecciosa/veterinária , Sequência de Bases , Variação Genética , Hemólise , Humanos , Meningite Pneumocócica/veterinária , Dados de Sequência Molecular , Compostos Orgânicos , Pneumonia Pneumocócica/veterinária , Sepse/veterinária , Homologia de Sequência do Ácido Nucleico , Infecções Estreptocócicas/microbiologia , Streptococcus suis/patogenicidade , Suínos
18.
J Pediatr Nurs ; 16(2): 137-45, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11326401

RESUMO

As part of a large study of the care of children in Australian, British, Indonesian, and Thai hospitals, qualitative methods were used to examine differences influenced by culture. Two groups were surveyed: parents of hospitalized children, and staff caring for them. Vignettes were used to invoke discussion, and content analysis was used to examine the data. Subjects were interviewed singly, or in focus groups. These interviews were audiotaped and transcribed verbatim. The data were explored by using content analysis to extract themes of understanding of cultural experiences. This article is the first of a two-part series, and includes a review of the literature, description of the methods used, and results of the parents' interviews. The staff results and discussion will be published in Part 2. Analysis revealed that parents in all countries were primarily concerned with treating the child's illness and the child's recovery. Parents were concerned with their work (employment), but this was a much larger consideration in Indonesia and Thailand, where no social security systems exist, than in Australia and Britain. Communication with staff was the most commonly mentioned theme for parents, indicating that irrespective of the culture in which the care was given, good communication between parents and staff was of paramount importance.


Assuntos
Atitude do Pessoal de Saúde , Atitude Frente a Saúde , Criança Hospitalizada/psicologia , Recursos Humanos de Enfermagem Hospitalar/psicologia , Pais/psicologia , Enfermagem Pediátrica/normas , Qualidade da Assistência à Saúde , Adolescente , Adulto , Austrália , Criança , Pré-Escolar , Comunicação , Comparação Transcultural , Feminino , Humanos , Indonésia , Lactente , Masculino , Pesquisa Metodológica em Enfermagem , Enfermagem Pediátrica/métodos , Relações Profissional-Família , Inquéritos e Questionários , Tailândia , Reino Unido
19.
J Burn Care Rehabil ; 22(2): 165-78;discussion 163-4, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11302606

RESUMO

The New York City Fire Department (FDNY) is the largest fire department in the United States. In 1996, FDNY added the thermal protective hood to its modern protective uniform. The purpose of this study is to determine 1) the effectiveness of hoods in reducing head burns and 2) whether hood water content (dry, damp, or saturated) affects the level of thermal protection. Laboratory tests (radiant heat performance, thermal protective performance, and fully dressed manikin) and FDNY field results were used. Laboratory tests evaluated 4 different conditions (no hood, dry, damp, and saturated hoods) exposed to 4 different heat fluxes (0.1, 0.25, 0.5, and 2.0 cal/cm2/sec) equivalent to approximate air temperatures of 200, 400, 600, and 2,250 degrees F. Field results compared FDNY head burns during 3 winters wearing the hood to 3 winters without hood. Wearing a hood dramatically reduced head burns. This was true for all laboratory tests, at all heat flux exposures, and all hood water content conditions. At 0.1 cal/cm2/sec, dry hoods were superior to wet hoods. At all other heat flux exposures, thermal protection was either not significantly different between water content conditions or improved as water content increased. Confirming these laboratory tests, FDNY field results showed significant decreases in neck burns (by 54%), ear burns (by 60%), and head burn totals (by 46%). Based on combined laboratory and field results, we strongly recommend the use of modern thermal protective hoods.


Assuntos
Queimaduras/epidemiologia , Queimaduras/prevenção & controle , Doenças Profissionais/epidemiologia , Doenças Profissionais/prevenção & controle , Roupa de Proteção , Distribuição de Qui-Quadrado , Incêndios , Cabeça , Humanos , Escala de Gravidade do Ferimento , Masculino , Cidade de Nova Iorque/epidemiologia , Fatores de Risco , Estatísticas não Paramétricas , Água/análise
20.
J Hum Evol ; 41(6): 545-76, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11782109

RESUMO

Among the best known of recently extinct Malagasy lemurs is Archaeolemur, which is represented by many hundreds of specimens. The phylogenetic affinities of this taxon are unclear, especially in light of recent preliminary analysis of ancient DNA which does not support its previously accepted close relationship with the living Indridae. We examined the nearly complete skeletons of two adults and one juvenile and other less complete specimens to reconstruct aspects of the ontogeny of Archaeolemur. To compare the development of Archaeolemur to that of living strepsirrhines we collected data on Propithecus verreauxi, Eulemur fulvus, and Lemur catta. Additionally, because Archaeolemur exhibits some morphological convergences with distantly related papionins, we tested for convergence in the developmental patterns of Archaeolemur and Macaca fascicularis. Data include the status of tooth eruption, craniofacial sutural closure, and postcranial epiphyseal fusion, as well as linear measurements. We used discriminant function analysis and other tools to explore ontogenetic similarities and differences. The adaptive and phylogenetic significance of ontogenetic information is discussed. Our analysis shows that Archaeolemur displays a clear strepsirrhine pattern of development with only minor macaque convergences. Among the Strepsirrhini, Archaeolemur is slightly more similar developmentally to E. fulvus and L. catta than to P. verreauxi. Some of the distinctive features of the ontogeny of Archaeolemur may be related to diet, while others bear apparent testimony to a relatively rapid absolute pace of growth and development.


Assuntos
Adaptação Fisiológica , Lemur/anatomia & histologia , Filogenia , Animais , Face/anatomia & histologia , Feminino , Fósseis , Lemur/crescimento & desenvolvimento , Crânio/anatomia & histologia , Erupção Dentária
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